The present invention relates to methods and means of fire extinguishing and may be applicable to enclosed compartments, for example, stationary depot premises, laboratories, baggage and engineering compartments of transportation facilities, etc.
At the present time there are known methods for fire extinguishing in enclosed compartments wherein the fire extinguishing medium is distributed over the compartment upon operation of a fire detector.
The fire extinguishing medium is distributed over the compartment in different ways, for example, by spraying the extinguishant over the compartment from storage cylinders through sprinkler heads (cf. British Pat. No. 1,053,920; U.S. Pat. Nos. 3,811,511; 3,878,897).
Installations for accomplishing this method utilize temperature indicators (fire detectors), fire alarm amplifiers, extinguishant storage tanks, electric cocks, pipe lines and extinguishant sprinkler heads. These installations become operable automatically or manually.
However, installations using a great number of components become complex, which reduces their reliability and efficiency, as their operation is dependent upon the reliability of all units incorporated thereinto. Moreover, said system requires a large useful space to arrange the units, is complicated in operation, has a large mass, may be applicable, substantially, in stationary premises and consumes a great amount of fire extinguishing compound.
There is also known a method for fire extinguishing in an enclosed compartment (cf. French Pat. No. 2,076,336) which utilizes a directed explosion to deliver an extinguishant to the source of the fire. An appliance accomplishing this method incorporates a container of extinguishant in solid state (in powder), a fuse placed outside the container and made in the form of a pyrotechnic chain, and an explosive charge situated inside the container which explodes upon operation of the pyrotechnic chain to expel the fire extinguishing powder.
However, this method and appliance for fire extinguishing does not provide a means for producing a noncombustible atmosphere in the compartment or to discharge the powder directly into the inner hemisphere of the container, to quench a fire only within the preset radius of action, i.e., in that area where the extinguishing powder is deposited directly on the source of the fire. The space beyond the reach of the powder remains on fire. The effective use of the fire extinguishant is limited. Furthermore, the fire extinguishing appliance is put in operation through a chain of intermediate links. The failure of one of these intermediate links may disturb the operation of the whole appliance, which reduces its dependability.
It is an object of the present invention to overcome the above disadvantages.
The principal object of this invention is to provide a reliable and efficient method of extinguishing fire in an enclosed compartment.
Another object of the invention is to provide a method of fire extinguishing which will produce a noncombustible atmosphere in the entire volume of the compartment without regard to where the fire arises and its extent at the time the appliance becomes operable.
Yet another object of the invention is the provision of an appliance for fire fighting which will allow for efficient and reliable use of a fire extinguishant.
To accomplish the foregoing and related objects a method of fire extinguishing in an enclosed compartment resides in a fire extinguishant placed in an individual container which is distributed over the compartment after the fuse ignition. According to the invention, the fire extinguishant is a chemically active inhibitor in liquid state confined in thermoplastic miniature capsules, which are distributed over the compartment and changed to a gaseous state under the influence of the temperature rising in the container after the fuze ignition, rupturing the capsule material and evaporating the inhibitor whose vapors leave the container and produce a noncombustible atmosphere in the compartment.
The fire extinguishant kept (stored) in the miniature capsules stays effective for a long period of time without the necessity for special sealed vessels.
The thermoplastic nature of the miniature capsules makes it possible to rapidly break the miniature capsules, to transform the liquid chemically active inhibitor to a gaseous state and to distribute it over the compartment under the influence of the temperature of the burning fuse and thermal charge and the influence of open flames in the compartment.
The five extinguishant (the chemically active inhibitor) distributed over the compartment in the gaseous state provides a means for reliable fire control by producing in the compartment the neutral noncombustible atmosphere with a minimum consumption of the extinguishant thereby making it impossible for the fire to begin again in the compartment for a definite period of time depending upon the compartment ventilation rate.
It is expedient that the chemically active inhibitor be liquid freon since liquid freon quickly turns to a gaseous state at ambient temperature and considerably expands in volume, which makes it possible to produce the noncombustible atmosphere in the compartment with the use of small amounts of the fire extinguishant.
It is also expedient that liquid freon be confined in the miniature capsules under pressure to provide for a more intensive breaking-up of the miniature capsules, distribution of freon over the compartment and creation of the non-combustible atmosphere.
An appliance designed for accomplishing the proposed method comprises an extinguishant container fastened in a compartment, a fuse placed outside the container responding to infrared radiation, and a charge placed inside the container to distribute the extinghishant over the compartment after ignition of the fuse. The invention utilizes as a fire extinguishant, a chemically active inhibitor in a liquid state confined in miniature capsules made from a thermoplastic material, and as a charge, a thermal charge made in the form of a rod of a highly inflammable oxygen-containing substance, which raises the temperature in the container after ignition of the fuse to cause the miniature capsules to break and the inhibitor to change from a liquid to a gas, the container being gas-permeable to allow the gaseous inhibitor to escape into the compartment and to produce the noncombustible atmosphere therein.
Thus, the appliance provides a simple means for accomplishing the proposed method and for producing the noncombustible atmosphere in the compartment.
In accordance with the invention, a thermal charge is placed in a perforated sleeve fixed in a container with its open butt end extending from the container and meant for securing a fuse, which makes it possible to create optimum conditions for using the thermal energy of the thermal charge to break the miniature capsules, to evaporate the inhibitor and to distribute it over the compartment.
It is expedient that in the perforated sleeve, between the thermal charge and fuse there be a non-return valve opening in the direction of the thermal charge, which eliminates leakage of combustible gases beyond the container and allows the thermal charge energy to be used more completely to break the miniature capsules and to evaporate the inhibitor.
The invention is also characterized by the thermal charge and fuse being made in the form of a rod thereby enhancing the operating efficiency of the appliance and simplifying its design.
The invention is further characterized by the fuse which may be made in the form of several rods fixed in a hemispherical shell fastened to the open butt end of the perforated sleeve.
It is expedient that the fuse portion protruding beyond the container be combined within an envelope made from highly heat-conducting material which does not interfere with the fuse ignition as prevent the discharge of hot gases into the compartment.
Thus, the proposed method and appliance for fire extinguishing in an enclosed compartment provides a means for quickly quenching fires, requires a lesser amount of an extinguishant and is reliable in operation.